You breathe about 20,000 times a day without thinking — but what if that automatic act could be trained to lower your blood pressure, sharpen your thinking, and even strengthen your heart? Dr. Lawrence Cahalin, clinical professor of physical therapy at the University of Miami and a Fellow of the American Physical Therapy Association and the American Heart Association, has spent his career studying exactly that. His research on respiratory muscle training is revealing just how much the breath influences nearly every system in the body.
In this conversation, Dr. Cahalin joins Dr. Brent Anderson to explore the science behind training your breathing muscles — not just for lung health, but for cognitive performance, cardiovascular function, and healthy aging. They discuss why a slightly irregular heartbeat during deep breathing is actually a sign of a healthy nervous system, how weak breathing muscles can literally steal blood flow from your legs, and what everyday breath training tools look like for patients and athletes alike. They also explore the emerging research on Wim Hof breathing, the connection between breath and sleep quality, and why ancient practices like Pilates, yoga, and qigong may have been onto something science is only now catching up to.
In this episode:
Resources mentioned:
00:00 Intro We breathe 20,000 times a day without thinking about it — yet this automatic act can be trained, strengthened, and optimized
00:23 Guest Introduction Dr. Lawrence Cahalin’s background: clinical professor at University of Miami, board-certified cardiopulmonary specialist, fellow of the APTA and American Heart Association, PhD in gerontology
01:16 Episode Overview Respiratory muscle training and its effects on cognition, heart rate variability, blood pressure, and autonomic nervous system function — and why breath may be the most accessible training tool we have
02:02 Welcome & Sponsor Dr. Brent intro and Polestar Pilates sponsorship
03:29 Conversation Begins Larry’s latest systematic review on respiratory muscle training and cognitive performance — and why breath is one of the most powerful ancient tools now being validated by evidence
04:59 Live Pulse Demo Larry guides Dr. Brent through a real-time experiment: taking your pulse and feeling it change with deep breathing
05:45 Sinus Arrhythmia & Heart Rate Variability Why a slightly irregular pulse during deep breathing is a sign of good health — and what it tells us about autonomic nervous system function
07:44 The Mechanics of Breath How diaphragm movement creates pressure changes that fill the lungs, draw blood into the heart, and influence the autonomic nervous system
09:43 The Ribcage, the Heart & Pilates Why thoracic movement matters — and how Pilates positions like roll-ups, swan, and rotation affect circulation around the heart and lungs
11:58 Breath Strategies: Does the Type Matter? Chest breathing vs. diaphragmatic vs. belly breath — and whether strategy affects how well vagal and stress-reduction techniques actually work
13:37 The Research: Doug Seals at CU Boulder High-intensity inspiratory muscle training at 60–80% maximal capacity improves blood pressure, nitric oxide, cerebral vascular reactivity, and mitochondrial metabolism — from breathing alone
15:10 Reframing Breath Capacity “Most bad breathers I know are dead” — how to remove fear from the conversation while opening the door to meaningful improvement
17:00 Larry’s Research at University of Miami Congenital heart disease in children, low back pain, heart failure, and metabolomics — including the first paper on fat oxidation through RMT
17:54 What Is Respiratory Muscle Training? What RMT looks like in practice, how threshold and spring-loaded devices work, and who can benefit — including people who can’t walk or exercise
21:22 The Respiratory Metaboreflex How weak breathing muscles steal blood from the legs — and why strengthening them allows people to walk farther with less shortness of breath
26:09 Contraindications & Devices The Pro2, Powerbreathe, and threshold devices; when to consult a cardiologist first; and a DIY COVID-era option using a $10 sphygmomanometer
27:02 Athletes, Ice Hockey & Cognitive Clarity RMT improved skating performance — and players reported being able to see and think more clearly on the ice
27:43 Breath, Brain Blood Flow & Cognition Inhalation draws venous blood out of the brain; exhalation drives arterial blood in — and respiratory muscle performance correlates significantly with MoCA, NeuroTrax, and R-band cognitive scores
33:03 Wim Hof Breathing: What the Literature Says Hyperventilation, breath holding, intermittent hypoxia, BDNF, and VEGF — what research actually shows and where the evidence is still developing
36:34 Self-Efficacy, Movement & Pain Lessons from Pilates and chronic low back pain research: physical measures weren’t predictive of recovery — self-efficacy was, and successful movement experiences are what shift it
38:33 Ancient Wisdom, Modern Validation Pilates, yoga, Tai Chi, Qigong — breath techniques embedded for thousands of years that science is only now confirming, including cognitive performance gains from RMT
43:13 Entrainment, Sleep & the Nervous System How breath can synchronize with EEG brain signals — and what this means for fragmented sleep, neural efficiency, and a teaser on vagal nerve research ahead
45:55 Closing Reflections Breath as both stress reducer and energizer; the promise of RMT for cognition and aging; Joseph Pilates’ 1940s formula for health — movement, nutrition, sleep, hygiene, fresh air, and play
49:27 Outro Leave a review, follow Dr. Brent at @drbrentpt, Principles of Movement on Amazon, and a final reminder to live aligned and be kind
PhD, PT, CCS, FAPTA, FAHA
Lawrence P. Cahalin PhD, PT, CCS, FAPTA, FAHA: Dr. Cahalin is a physical therapist who is a clinical professor in the Department of Physical Therapy at the Miller School of Medicine, University of Miami. He is a Board Certified Cardiopulmonary Clinical Specialist with a varied research background and a PhD in Gerontology from the University of Massachusetts Boston. His research endeavors include studies of exercise testing, exercise training, and the assessment of functional capacity as well as testing and training of the respiratory muscles. His training in both physical therapy and gerontology has provided him with clinical and research skills to better appreciate and understand the effects of aging in older adults with and without various diseases.
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